#include<stdio.h>
#include<stdlib.h>
typedef struct tree
{
     int  data;
  struct tree *leftchild;
  struct tree *rightchild;
} tree,*treepoint;
void initTree(treepoint *p);
void creatTree(treepoint *p);
void xian(treepoint *p);
void zhong(treepoint *p);
void hou(treepoint *p);

